湖北赤壁金银山锂矿赋存状态及矿床成因

The occurrence status and genesis of the Jinyinshan lithium deposit in Chibi,Hubei

金银山锂矿床位于湖北省赤壁市境内,矿床受近东西断裂F9控制明显,含矿岩性以硅化压碎岩、碎裂粉砂质板岩、碎裂泥质板岩、变质粉砂岩以及煌斑岩为主。目前在本区碎裂粉砂质板岩中发现锂绿泥石已有报道,但对区内所有含矿岩性,特别是煌斑岩中锂是以何种形式存在缺乏研究。文章选取了区内所有含矿岩性进行了扫描电镜分析,认为本区无云母类矿物。开展了原位X射线衍射(XRD)研究,发现了锂绿泥石的特征峰。开展了原位微量元素分析(LA-ICPMS)等分析,发现Li和Al_(2)O_(3)呈强正相关关系,证实了本区锂是以锂绿泥石的形式存在。此外,本区锂绿泥石主要充填于石英颗粒之间或是在橄榄石的假晶中,产状呈鳞片状、竹叶状,与热液型绿泥石成因特征完全吻合,因此推断金银山矿区锂绿泥石为热液成因。由于南部15 km左右正是与稀有金属成矿关系密切的幕阜山复式岩体,成矿物质可能来源于南部岩体,后续在矿产勘查的过程中要注意在F9断裂与岩体之间寻找类似的锂矿床。

The Jinyinshan lithium deposit is located in Chibi City,Hubei Province.The ore-bearing rocks are mainly silicified cataclasite,cataclastic silty slate,cataclastic argillaceous slate,metamorphic siltstone,and lamprophyre.It has been reported that the cookeite is found in the cataclastic silty slate in this area,However,there is a lack of research on the form of lithium in all ore-bearing lithology,especially in lamprophyre.The article selected all ore-bearing lithology in the area for scanning electron microscopy analysis,and it is believed that there are no mica minerals in this area.In situ X-ray diffraction(XRD)study was carried out and the characteristic peak of cookeite was found.In situ trace element analysis(LA-ICPMS)and other analyses have been carried out.It is found that Li and Al_(2)O_(3) have a strong positive correlation,which confirms that lithium in this area exists in the form of cookeite.In addition,cookeite in this area is mainly filled between quartz grains or in olivine pseudocrystals,and its occurrence is scaly and bamboo leaves,It is completely consistent with the genetic characteristics of the hydrothermal cookeite,so it is inferred that cookeite in Jinyinshan mining area is of hydrothermal origin.As the Mufu Mountains complex rock body,which is closely related to rare metal mineralization,is about 15 km away from the south,the ore-forming materials may come from the southern rock body,In the subsequent process of mineral exploration,attention should be paid to searching for similar lithium deposits between the F9 fault and the rock mass.